BLOB column says undefined

Question

Hi .
when i create a BLOB column in the table and describe the structure it says undefined. how do i fix that. also if someone can let me know how to update a RTF content from a VB to the BLOB column in the oracle table?? Tons of thanks in advance

Answer 1

You can write a BLOB- VB to Oracle database using ADO function in VB. Search in MSDN for help on BLOB function. They have a ready eg.
Just in case you don't find it.
Here it is:
Just copy paste this in a form with text boxes for all ODBC parameters.
I think you cannot read directly from a BLOB column. Don't forget to initiate a BLOB column like:
/*LOB table for storing files*/
Drop table FileColumn;
Create table FileColumn
( REPQUE_ID NUMBER(10) NOT NULL ,
RepText_blob BLOB default empty_blob()
Storage (initial 50K next 50K pctincrease 0)
tablespace TEST31ORA
lob(RepText_blob) store as
(tablespace ACCOUNT4
Storage (initial 100k next 100k pctincrease 0)
chunk 16k pctversion 10 nocache logging);
/*initialize LOB locator by making it not null, use empty lob, this will
insert the locator value in that column
I did this initialize in create table script, so that I can do the bulk insert
One can do bulk inserts if there are no rows before
insert into FileColumn
values(1, empty_blob()); */
Option Explicit
Const BlockSize = 32768
' FUNCTION: ReadBLOB()
' PURPOSE:
' Reads a BLOB from a disk file and stores the contents in the
' specified table and field.
' PREREQUISITES:
' The specified table with the OLE object field to contain the
' binary data must be opened in Visual Basic code (Access Basic
' code in Microsoft Access 2.0 and earlier) and the correct record
' navigated to prior to calling the ReadBLOB() function.
' ARGUMENTS:
' Source - The path and filename of the binary information
' to be read and stored.
' T - The table object to store the data in.
' Field - The OLE object field in table T to store the data in.
' RETURN:
' The number of bytes read from the Source file.
Function ReadBLOB(Source As String, T As Recordset, _
sField As String)
Dim NumBlocks As Integer, SourceFile As Integer, i As Integer
Dim FileLength As Long, LeftOver As Long
Dim FileData As String
Dim RetVal As Variant
On Error GoTo Err_ReadBLOB
' Open the source file.
SourceFile = FreeFile
Source = "c:\blob_file_folder\G63JR557.doc"
T = mwebRepOutput
sField = RepOut_Content
Open Source For Binary Access Read As SourceFile
' Get the length of the file.
FileLength = LOF(SourceFile)
If FileLength = 0 Then
ReadBLOB = 0
Exit Function
End If
' Calculate the number of blocks to read and leftover bytes.
NumBlocks = FileLength \ BlockSize
LeftOver = FileLength Mod BlockSize
' SysCmd is used to manipulate status bar meter.
RetVal = SysCmd(acSysCmdInitMeter, "Reading BLOB", _
FileLength \ 1000)
' Put first record in edit mode.
T.MoveFirst
T.Edit
' Read the leftover data, writing it to the table.
FileData = String$(LeftOver, 32)
Get SourceFile, , FileData
T(sField).AppendChunk (FileData)
RetVal = SysCmd(acSysCmdUpdateMeter, LeftOver / 1000)
' Read the remaining blocks of data, writing them to the table.
FileData = String$(BlockSize, 32)
For i = 1 To NumBlocks
Get SourceFile, , FileData
T(sField).AppendChunk (FileData)
RetVal = SysCmd(acSysCmdUpdateMeter, BlockSize * i / 1000)
Next i
' Update the record and terminate function.
T.Update
RetVal = SysCmd(acSysCmdRemoveMeter)
Close SourceFile
ReadBLOB = FileLength
Exit Function
Err_ReadBLOB:
ReadBLOB = -Err
Exit Function
End Function
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